This invention relates to an internal combustion engine provided with a fuel injection device and more particularly to improvements in the lubrication of fuel injected internal combustion engines.
The advantages of fuel injection have resulted in a substantial increase in the number of fuel injected internal combustion engines. Many injection systems embody mechanically driven injection pumps that are employed for metering an exact amount of fuel during each injection cycle. Although such devices have considerable advantage due to their exactness, it is desirable to lubricate the mechanical components of the injection pump. Although devices have been proposed for delivering lubricant to the mechanical components of the fuel injection pump, the devices of the type heretofore proposed have used this same flow of lubricant for lubricating the other components of the engine. As a result, there is an uneven flow of lubricant due to the cylical action of the injection pump and it is necessary to circulate larger amounts of lubricant than may actually be required for the lubricating function.
It is, therefore, a principal object of this invention to provide an improved lubricating system for the injection pump of a fuel injected internal combustion engine.
It is a yet further object of this invention to provide a fuel injection pump lubricating system in which the amount of lubricant delivered to the various components of the engine may be accurately controlled and only the necessary amounts of lubricant supplied.
Because of the aforenoted advantages of fuel injection, its use has also become widely adapted with two-cycle in addition to four-cycle internal combustion engines. As is commonly known, many two-cycle internal combustion engines lubricate a number of their internal components through the mixing of lubricant with the fuel. With conventional types of engines, this has necessitated the operator's mixing lubricant with the fuel and this has a number of disadvantages, which are believed to be obvious.
It is, therefore, a further object of this invention to provide a lubricating system for a two-cycle, fuel injected internal combustion engine wherein it is unnecessary to mix lubricant with the fuel by the operator.
It is a further object of this invention to provide an improved lubricating system for a two-cycle, fuel injection internal combustion engine wherein lubricant is automatically mixed with the fuel injected by the fuel injection pump.
In addition to providing a lubricating function for the engine, it has been found that the amount of fuel injected by an injection pump can vary significantly with the viscosity of the fuel. If only fuel is being injected, it may be difficult to provide adequate control for the amount of fuel injected, due to these viscosity changes, under all running and atmospheric conditions. It has been found, however, that these variations can be significantly reduced if an amount of lubricant is mixed with the fuel that is pumped by the injection pump.
It is, therefore, a further object of this invention to provide an improved and more accurate fuel injection system for an internal combustion engine.